A Tour of the Milky Way

Manuel Pichardo Marcano

he/him/his

Department of Physics and Astronomy

One-Third of Humanity Can't See the Milky Way

The legend

\Gamma \alpha\lambda\alpha\xi \acute{\iota}\alpha\varsigma \text{ from the greek } \gamma\acute{\alpha}\lambda\alpha \text{ (milk)}

Acáyouman:

Celestial Caiman

"Discovery" of the Milky Way

  • Galileo Galilei (1610):
    • “The Milky Way is nothing else but a mass of innumerable stars planted together in clusters.”
  • William Herschel (1784):

Center of the Galaxy

“It is believed that the great mass of the stars ... are arranged in the form of a lens-or bun-shaped system ... considerably flattened towards one plane ... the Sun occupies a fairly central position.”

—Arthur Eddington, 1914

"It is worthy of notice...that the brighter variables have longer periods.
      —Henrietta Swan Leavitt (1908)

A tool to measure distances

"It is worthy of notice...that the brighter variables have longer periods.
      —Henrietta Swan Leavitt (1908)

A tool to measure distances

Star Clusters

Globular Clusters

Variables in GCs

The Galactocentric Revolution

The center of the sidereal system is distant from the Earth.
      — Harlow Shapley  (1918)

Do the same with other regions

Current Model

How big is the Milky Way Galaxy?

The Milky Way (to scale)

How far is 100,000 light years?

  • 1 inch represents 5.5 light hours (Sun to Pluto)
    • 1 mile represents 40 light years

2,500 miles
represents
   100,000 light years

North America

And how thick is our Galaxy?

How thick is 1,000 light years?

If 2,500 miles represents 100,000 light years

 

        25 miles represents     1,000 light years

\sim 30 \text{ miles Lubbock to Levelland}

200 Billion Stars

Bird seeds 4 feet deep

The Tour

Dark Matter Halo

                No dark matter                                                      Dark matter

Globular Clusters

~150 known in the Milky Way

A Zoo of Exotic Objects

Gas around BH

Thank you

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